Epdcch candidate determining method and device

ABSTRACT

The present disclosure describes a physical downlink control channel (PDCCH) candidate determining method and device, and relates to the field of wireless communications, so as to avoid PDCCH blocking and improve reliability of control information transmission. The method of the present invention includes: determining an PDCCH resource set p in a subframe k, where the PDCCH resource set p includes N ECCE,p,k =q×r enhanced control channel elements (ECCEs), an PDCCH candidate of an PDCCH with an aggregation level being L corresponds to L ECCEs having consecutive reference numerals, and an PDCCH candidate is capable of carrying an PDCCH; and determining the number of PDCCH candidates at the aggregation level L of a carrier corresponding to an index Cellindex and an ECCE corresponding to each PDCCH candidate, where the ECCE corresponding to each PDCCH candidate at the aggregation level L is related to the index Cellindex.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/802,585, filed on Jul. 17, 2015, which is a continuation ofInternational Application No. PCT/CN2013/070731, filed on Jan. 18, 2013.All of the afore-mentioned patent applications are hereby incorporatedby reference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of wireless communications,and in particular, to an enhanced physical downlink control channel(Enhanced Physical Downlink Control Channel, EPDCCH) candidatedetermining method and device.

BACKGROUND

In a wireless communications system, a base station may carry an EPDCCHin a specific transmission resource, and send control informationrelated to a carrier to a UE by sending the EPDCCH; correspondingly, theUE may also find the EPDCCH in the specific transmission resource, so asto obtain related configuration information of the carrier from thefound EPDCCH by means of parsing.

Specifically, a base station determines an available EPDCCH resource setin a subframe, determines, according to an aggregation level of ato-be-transmitted EPDCCH and from the EPDCCH resource set, the number ofand an allocation manner of candidates corresponding to the transmissionof the aggregation level, places the to-be-transmitted EPDCCH in anycandidate and sends the to-be-transmitted EPDCCH to a UE.Correspondingly, after obtaining information of the EPDCCH resource set,the UE may also determine, according to the same manner, the number ofand an allocation manner of candidates corresponding to each aggregationlevel, and the UE may attempt to detect candidates of differentaggregation levels separately, so as to obtain related controlinformation of a carrier from a detected correct EPDCCH.

During implementation of the foregoing EPDCCH transmission, the inventorfinds that the prior art has at least the following problems: whenEPDCCHs of multiple carriers are sent in an EPDCCH resource set at thesame time, an allocation manner of candidates for carrying the EPDCCHsis determined for each carrier by using a same algorithm, and therefore,distribution locations of EPDCCH candidates of any two carriers at thesame aggregation level are completely the same, but an EPDCCH candidatecan only carry one EPDCCH; as a result, some EPDCCHs at the sameaggregation level are discarded, resulting in problems of EPDCCHblocking and unreliable transmission of control information.

SUMMARY

Embodiments of the present invention provide an EPDCCH transmissionmethod and device, so as to avoid EPDCCH blocking and improvereliability of control information transmission.

In order to achieve the foregoing objectives, the embodiments of thepresent invention adopt the following technical solutions:

A first aspect of the present invention provides an enhanced physicaldownlink control channel EPDCCH candidate determining method, which isused in a cross-carrier scheduling process, where an EPDCCH candidate onat least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The method includes:

determining the EPDCCH resource set p in a subframe k, where the EPDCCHresource set p includes q resource block pairs, each of the resourceblock pairs corresponds to r enhanced control channel elements ECCEs,q>=1, r>=1, N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCHresource set p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, .. . , N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH atthe aggregation level L corresponds to L ECCEs having consecutivereference numerals, and an EPDCCH candidate is capable of carrying anEPDCCH; and

determining the number of EPDCCH candidates at the aggregation level Lof a carrier corresponding to an index Cellindex and an ECCEcorresponding to each EPDCCH candidate, where the ECCE corresponding toeach EPDCCH candidate at the aggregation level L is related to the indexCellindex.

With reference to the first aspect of the present invention, in a firstpossible implementation manner, the determining the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidateincludes obtaining an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and theEPDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of EPDCCH candidates, of a user equipment UE corresponding to theEPDCCH candidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.

With reference to the first aspect of the present invention, in a secondpossible implementation manner, the determining the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidateincludes obtaining an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + {n_{Cellindex}\left\lfloor \frac{N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n is the number ofcarriers.

With reference to the first aspect of the present invention, in a thirdpossible implementation manner, the determining the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidateincludes obtaining an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m^{\prime} \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, m′=m·n+n_(Cellindex),and n is the number of carriers.

With reference to the first aspect of the present invention, the secondpossible implementation manner, or the third possible implementationmanner, in a fourth possible implementation manner,

n is the number Q of carriers of the user equipment, or

n is the number of schedulable carriers of the user equipment in theEPDCCH set p, including carriers activated and deactivated in the EPDCCHset p by the user equipment in the subframe k.

With reference to the first possible implementation manner, the secondpossible implementation manner, the third possible implementationmanner, or the fourth possible implementation manner of the first aspectof the present invention, in a fifth possible implementation manner,

n_(Cellindex) is a relative offset, which is related to the indexCellindex, of candidates having a same serial number between carriers;and

a value range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the D2 schedulable carriers includes carriers activated anddeactivated in the EPDCCH set p by the user equipment in the subframe k.

With reference to the first possible implementation manner, the secondpossible implementation manner, the third possible implementationmanner, the fourth possible implementation manner, or the fifth possibleimplementation manner of the first aspect of the present invention, in asixth possible implementation manner,

according to ascending order or descending order of the indexesCellindex of the carriers, a first serial number sequence, which issequentially numbered, is obtained starting from 0, and n_(Cellindex) isa serial number value of the carrier index Cellindex in the first serialnumber sequence.

With reference to the first possible implementation manner, the secondpossible implementation manner, the third possible implementationmanner, or the fourth possible implementation manner of the first aspectof the present invention, in a seventh possible implementation manner,

n_(Cellindex) is a value of the index Cellindex.

A second aspect of the present invention provides an enhanced physicaldownlink control channel EPDCCH candidate determining device, which isused in a cross-carrier scheduling process, where an EPDCCH candidate onat least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The device includes:

a first determining unit, configured to determine an EPDCCH resource setp in a subframe k, where the EPDCCH resource set p includes q resourceblock pairs, each of the resource block pairs corresponds to r enhancedcontrol channel elements ECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×r indicatesthe number of ECCEs in the EPDCCH resource set p, reference numerals ofthe N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . , N_(ECCE,p,k)−1 respectively,an EPDCCH candidate of the EPDCCH at the aggregation level L correspondsto L ECCEs having consecutive reference numerals, and an EPDCCHcandidate is capable of carrying an EPDCCH; and

a second determining unit, configured to determine the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidate inthe EPDCCH resource set p determined by the first determining unit,where the ECCE corresponding to each EPDCCH candidate at the aggregationlevel L is related to the index Cellindex.

With reference to the second aspect of the present invention, in a firstpossible implementation manner, the second determining unit is furtherconfigured to obtain an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and theEPDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of EPDCCH candidates, of a user equipment UE corresponding to theEPDCCH candidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.

With reference to the second aspect of the present invention, in asecond possible implementation manner, the second determining unit isfurther configured to obtain an ECCE corresponding to an m^(th) EPDCCHcandidate according to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + {n_{Cellindex}\left\lfloor \frac{N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n is the number ofcarriers.

With reference to the second aspect of the present invention, in a thirdpossible implementation manner, the second determining unit is furtherconfigured to obtain an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m^{\prime} \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, m′=m·n+n_(Cellindex),and n is the number of carriers.

With reference to the second and third possible implementation mannersof the second aspect of the present invention, in a fourth possibleimplementation manner,

n is the number Q of carriers of the user equipment, or

n is the number of schedulable carriers of the user equipment in theEPDCCH set p, including carriers activated and deactivated in the EPDCCHset p by the user equipment in the subframe k.

With reference to the first possible implementation manner, the secondpossible implementation manner, the third possible implementationmanner, or the fourth possible implementation manner of the secondaspect of the present invention, in a fifth possible implementationmanner,

n_(Cellindex) is a relative offset, which is related to the indexCellindex, of candidates having a same serial number between carriers;and

a value range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the D2 schedulable carriers includes carriers activated anddeactivated in the EPDCCH set p by the user equipment in the subframe k.

With reference to the first possible implementation manner, the secondpossible implementation manner, the third possible implementationmanner, the fourth possible implementation manner, or the fifth possibleimplementation manner of the second aspect of the present invention, ina sixth possible implementation manner,

according to ascending order or descending order of the indexesCellindex of the carriers, a first serial number sequence, which issequentially numbered, is obtained starting from 0, and n_(Cellindex) isa serial number value of the carrier index Cellindex in the first serialnumber sequence.

With reference to the first possible implementation manner, the secondpossible implementation manner, the third possible implementationmanner, or the fourth possible implementation manner of the secondaspect of the present invention, in a seventh possible implementationmanner,

n_(Cellindex) is a value of the index Cellindex.

A third aspect of the present invention provides an enhanced physicaldownlink control channel EPDCCH candidate determining device, which isused in a cross-carrier scheduling process, where an EPDCCH candidate onat least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The device includes:

a memory, configured to store program code used to determine an EPDCCHcandidate; and

a processor, configured to read and run the program code stored in thememory, where the program code is used to execute the followingoperations: determining the EPDCCH resource set p in a subframe k, wherethe EPDCCH resource set p includes q resource block pairs, each of theresource block pairs corresponds to r enhanced control channel elementsECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×r indicates the number of ECCEs in theEPDCCH resource set p, reference numerals of the N_(ECCE,p,k) ECCEs are0, 1, 2, . . . , N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of theEPDCCH at the aggregation level L corresponds to L ECCEs havingconsecutive reference numerals, and an EPDCCH candidate is capable ofcarrying an EPDCCH; and

determining the number of EPDCCH candidates at the aggregation level Lof a carrier corresponding to an index Cellindex and an ECCEcorresponding to each EPDCCH candidate, where the ECCE corresponding toeach EPDCCH candidate at the aggregation level L is related to the indexCellindex.

With reference to the third aspect of the present invention, in a firstpossible implementation manner, the determining the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidateincludes obtaining an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and theEPDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of EPDCCH candidates, of a user equipment UE corresponding to theEPDCCH candidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and Cellindex is apredefined candidate offset of the carrier corresponding to the indexCellindex.

With reference to the third aspect of the present invention, in a secondpossible implementation manner, the determining the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidateincludes obtaining an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + {n_{Cellindex}\left\lfloor \frac{N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n is the number ofcarriers.

With reference to the third aspect of the present invention, in a thirdpossible implementation manner, the determining the number of EPDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an ECCE corresponding to each EPDCCH candidateincludes obtaining an ECCE corresponding to an m^(th) EPDCCH candidateaccording to the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m^{\prime} \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, m′=m·n+n_(Cellindex),and n is the number of carriers.

With reference to the second possible implementation manner or the thirdpossible implementation manner of the third aspect of the presentinvention, in a fourth possible implementation manner,

n is the number Q of carriers of the user equipment, or

n is the number of schedulable carriers of the user equipment in theEPDCCH set p, including carriers activated and deactivated in the EPDCCHset p by the user equipment in the subframe k.

With reference to the second possible implementation manner, the thirdpossible implementation manner, or the fourth possible implementationmanner of the third aspect of the present invention, in a fifth possibleimplementation manner,

n_(Cellindex) is a relative offset, which is related to the indexCellindex, of candidates having a same serial number between carriers;and

a value range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the D2 schedulable carriers includes carriers activated anddeactivated in the EPDCCH set p by the user equipment in the subframe k.

With reference to the second possible implementation manner, the thirdpossible implementation manner, the fourth possible implementationmanner, or the fifth possible implementation manner of the third aspectof the present invention, in a sixth possible implementation manner,

according to ascending order or descending order of the indexesCellindex of the carriers, a first serial number sequence, which issequentially numbered, is obtained starting from 0, and n_(Cellindex) isa serial number value of the carrier index Cellindex in the first serialnumber sequence.

With reference to the second possible implementation manner, the thirdpossible implementation manner, or the fourth possible implementationmanner of the third aspect of the present invention, in a seventhpossible implementation manner,

n_(Cellindex) is a value of the index Cellindex.

A fourth aspect of the present invention provides a base station, whichis used in a cross-carrier scheduling process, where an EPDCCH candidateon at least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The base station includes: an EPDCCH candidatedetermining device and a sending device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The sending device is configured to place an EPDCCH of a carrier, whoseindex Cellindex is a carrier indicator field index Cellindex, in oneEPDCCH candidate among EPDCCH candidates determined by the EPDCCHcandidate determining device, and send the EPDCCH.

A fifth aspect of the present invention provides a user equipment UE,which is used in a cross-carrier scheduling process, where an EPDCCHcandidate on at least two carriers is located in an EPDCCH resource seton one carrier among the at least two carriers, an aggregation level ofthe EPDCCH is L, and L>=1. The UE includes an EPDCCH candidatedetermining device and a receiving device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The receiving device is configured to detect the EPDCCH candidatedetermined by the EPDCCH candidate determining device; when a correctEPDCCH is detected, obtain control information of the carrier, whoseindex Cellindex is a carrier indicator field index Cellindex, from thecorrect EPDCCH by means of parsing; and when no correct EPDCCH isdetected, instruct the EPDCCH candidate determining device to continueto determine, by using another aggregation level, the number of EPDCCHcandidates at the another aggregation level of the carrier correspondingto the index Cellindex and an ECCE corresponding to each EPDCCHcandidate until a correct EPDCCH is detected or the q×r ECCEs aretraversed.

A sixth aspect of the present invention provides an enhanced commonsearch space ECSS resource determining method, including:

configuring, by using higher layer signaling, or determining, accordingto a predetermined rule, the number N of physical resources occupied byan ECSS; and

determining locations of the physical resources occupied by the ECSS,where the locations of the physical resources occupied by the ECSS arepredefined locations related to at least one of a physical or virtualcell ID, a subframe timeslot number, and a system bandwidth, or randomlocations related to at least one of a physical or virtual cell ID, asubframe timeslot number, and a system bandwidth.

With reference to the sixth aspect of the present invention, in a firstpossible implementation manner, the determining, according to apredetermined rule, the number N of physical resources occupied by theECSS includes that:

the number N of the physical resources occupied by the ECSS is relatedto the system bandwidth.

With reference to the sixth aspect of the present invention, in a secondpossible implementation manner, the locations of the physical resourcesoccupied by the ECSS being predefined locations related to at least oneof a physical cell ID, a virtual cell ID, a subframe timeslot number,and a system bandwidth includes that:

a fixed deviation exists between physical resource blocks occupied by anECSS of each cell, and under different subframe timeslot numbers ordifferent physical or virtual cell IDs, physical resource blocksoccupied by an ECSS are different.

With reference to the second possible implementation manner of the sixthaspect of the present invention, in a third possible implementationmanner, the locations of the physical resources occupied by the ECSSare:

Y _(k,i)=(Y _(k-1,0) +X)mod N _(RB)+(└N _(RB) /N┘)*i

where Y_(k-1,0) is a serial number of a first physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, Y_(−1,0) is apredefined value being the same for all cells, X is a virtual cell ID, Nis the number of physical resource blocks occupied by the ECSS, i=0, 1,. . . , N−1, and N_(RB) is the system bandwidth.

With reference to the second possible implementation manner of the sixthaspect of the present invention, in a fourth possible implementationmanner, the locations of the physical resources occupied by the ECSSare:

Y _(k,i)=(Y _(k-1,i)+offset)mod N _(RB)

where Y_(k-1,i) is a serial number of an i^(th) physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, offset may be avirtual cell ID or a subframe timeslot number, N is the number ofphysical resource blocks occupied by the ECSS, i=0, 1, . . . , N−1, andN_(RB) is the system bandwidth.

With reference to the sixth aspect of the present invention, in a fifthpossible implementation manner, the physical resources occupied by theECSS being random locations related to at least one of a physical orvirtual cell ID, a subframe timeslot number, and a system bandwidthincludes that:

each physical resource occupied by the ECSS is randomly generated;

alternatively, a first physical resource occupied by the ECSS israndomly generated.

With reference to the fifth possible implementation manner of the sixthaspect of the present invention, in a sixth possible implementationmanner, the locations of the physical resources occupied by the ECSSare:

Y _(k,i)=((A _(i) ·Y _(k-1,i))mod D _(i))mod N _(RB)

where Y_(−1,i)=X, A_(i)=A+i*offset A=39827, D_(i)=D+i*offset D=65537,k=└n_(s)/2┘, n_(s) is a number of a timeslot in a subframe, X is avirtual cell ID, N is the number of physical resource blocks occupied bythe ECSS, i=0, 1, . . . , N−1, and N_(RB) is the system bandwidth.

With reference to the fifth possible implementation manner of the sixthaspect of the present invention, in a seventh possible implementationmanner, the first physical resource occupied by the ECSS is:

Y _(k)=((A·Y _(k-1))mod D)mod N _(RB)

where Y⁻¹=X, X is a virtual cell ID, A=39827, D=65537, k=└n_(s)/2┘,n_(s) is a number of a timeslot in a subframe, other physical resourcesoccupied by the ECSS are: (Y_(k)+└N_(RB)/N┘·i)mod N_(RB), N is thenumber of physical resource blocks occupied by the ECSS, i=0, 1, . . . ,N−1, and N_(RB) is the system bandwidth.

With reference to the sixth aspect of the present invention, in aneighth possible implementation manner, the physical resources occupiedby the ECSS being random locations related to at least one of a physicalor virtual cell ID, a subframe timeslot number, and a system bandwidthincludes that:

the whole system bandwidth is divided into N groups of predefinedresources not overlapping with each other, and physical resourcesoccupied by the ECSS of different cells in different subframes are arandom group, determined by a random function and related to at leastone of the physical or virtual cell ID, the subframe timeslot number,and the system bandwidth, among the resource groups.

With reference to the eighth possible implementation manner of the sixthaspect of the present invention, in a ninth possible implementationmanner, the random function is a hash (Hash) function.

A seventh aspect of the present invention provides an ECSS resourcedetermining device, including:

a third determining unit, adapted to configure, by using higher layersignaling, or determine, according to a predetermined rule, the number Nof physical resources occupied by the ECSS; and

a fourth determining unit, configured to determine, according to thenumber N, determined by the third determining unit, of physicalresources occupied by the ECSS, locations of the physical resourcesoccupied by the ECSS, where the locations of the physical resourcesoccupied by the ECSS are predefined locations related to at least one ofa physical or virtual cell ID, a subframe timeslot number, and a systembandwidth, or random locations related to at least one of a physical orvirtual cell ID, a subframe timeslot number, and a system bandwidth.

With reference to the seventh aspect of the present invention, in afirst possible implementation manner,

the number N of the physical resources occupied by the ECSS is relatedto the system bandwidth.

With reference to the seventh aspect of the present invention, in asecond possible implementation manner, the locations of the physicalresources occupied by the ECSS being predefined locations related to atleast one of a physical cell ID, a virtual cell ID, a subframe timeslotnumber, and a system bandwidth includes that:

a fixed deviation exists between physical resource blocks occupied by anECSS of each cell, and under different subframe timeslot numbers ordifferent physical or virtual cell IDs, physical resource blocksoccupied by an ECSS are different.

With reference to the second possible implementation manner of theseventh aspect of the present invention, in a third possibleimplementation manner, the locations, determined by the fourthdetermining unit, of the physical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,0) +X)mod N _(RB)+(└N _(RB) /N┘)*i

where Y_(k-1,0) is a serial number of a first physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, Y_(−1,0) is apredefined value being the same for all cells, X is a virtual cell ID, Nis the number of physical resource blocks occupied by the ECSS, i=0, 1,. . . , N−1, and N_(RB) is the system bandwidth.

With reference to the second possible implementation manner of theseventh aspect of the present invention, in a fourth possibleimplementation manner, the locations, determined by the fourthdetermining unit, of the physical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,i)+offset)mod N _(RB)

where Y_(k-1,i) is a serial number of an i^(th) physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, offset may be avirtual cell ID or a subframe timeslot number, N is the number ofphysical resource blocks occupied by the ECSS, i=0, 1, . . . , N−1, andN_(RB) is the system bandwidth.

With reference to the seventh aspect of the present invention, in afifth possible implementation manner, the physical resources occupied bythe ECSS being random locations related to at least one of a physical orvirtual cell ID, a subframe timeslot number, and a system bandwidthincludes that:

each physical resource occupied by the ECSS is randomly generated;

alternatively, a first physical resource occupied by the ECSS israndomly generated.

With reference to the fifth possible implementation manner of theseventh aspect of the present invention, in a sixth possibleimplementation manner, the locations, determined by the fourthdetermining unit, of the physical resources occupied by the ECSS are:

Y _(k,i)=((A _(i) ·Y _(k-1,i))mod D _(i))mod N _(RB)

where Y_(−1,i)=X, A_(i)=A+i*offset, A=39827, D_(i)=D+i*offset, D=65537,k=└n_(s)/2┘, n_(s) is a number of a timeslot in a subframe, X is avirtual cell ID, N is the number of physical resource blocks occupied bythe ECSS, i=0, 1, . . . , N−1, and N_(RB) is the system bandwidth.

With reference to the fifth possible implementation manner of theseventh aspect of the present invention, in a seventh possibleimplementation manner, the first physical resource, determined by thefourth determining unit, occupied by the ECSS is:

Y _(k)=((A·Y _(k-1))mod D)mod N _(RB)

where Y⁻¹=X, X is a virtual cell ID, A=39827, D=65537, k=└n_(s)/2┘,n_(s) is a number of a timeslot in a subframe, other physical resourcesoccupied by the ECSS are: (Y_(k)+└N_(RB)/N┘·i)mod N_(RB), N is thenumber of physical resource blocks occupied by the ECSS, i=0, 1, . . . ,N−1, and N_(RB) is the system bandwidth.

With reference to the seventh aspect of the present invention, in aneighth possible implementation manner, the physical resources occupiedby the ECSS being random locations related to at least one of a physicalor virtual cell ID, a subframe timeslot number, and a system bandwidthincludes that:

the whole system bandwidth is divided into N groups of predefinedresources not overlapping with each other, and physical resourcesoccupied by the ECSS of different cells in different subframes are arandom group, determined by a random function and related to at leastone of the physical or virtual cell ID, the subframe timeslot number,and the system bandwidth, among the resource groups.

With reference to the eighth possible implementation manner of theseventh aspect of the present invention, in a ninth possibleimplementation manner, the random function is a hash (Hash) function.

An eighth aspect of the present invention provides an enhanced commonsearch space ECSS resource determining device, including:

a memory, configured to store program code used to determine an ECSSresource; and

a processor, configured to read and run the program code stored in thememory, where the program code is used to execute the followingoperations: configuring, by using higher layer signaling, ordetermining, according to a predetermined rule, the number N of physicalresources occupied by the ECSS; and

determining locations of the physical resources occupied by the ECSS,where the locations of the physical resources occupied by the ECSS arepredefined locations related to at least one of a physical or virtualcell ID, a subframe timeslot number, and a system bandwidth, or randomlocations related to at least one of a physical or virtual cell ID, asubframe timeslot number, and a system bandwidth.

With reference to the eighth aspect of the present invention, in a firstpossible implementation manner,

the number N of the physical resources occupied by the ECSS is relatedto the system bandwidth.

With reference to the eighth aspect of the present invention, in asecond possible implementation manner, the locations of the physicalresources occupied by the ECSS being predefined locations related to atleast one of a physical cell ID, a virtual cell ID, a subframe timeslotnumber, and a system bandwidth includes that:

a fixed deviation exists between physical resource blocks occupied by anECSS of each cell, and under different subframe timeslot numbers ordifferent physical or virtual cell IDs, physical resource blocksoccupied by an ECSS are different.

With reference to the second possible implementation manner of theeighth aspect of the present invention, in a third possibleimplementation manner, the locations, determined by the processor, ofthe physical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,0) +X)mod N _(RB)+(└N _(RB) /N┘)*i

where Y_(k-1,0) is a serial number of a first physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, Y_(−1,0) is apredefined value being the same for all cells, X is a virtual cell ID, Nis the number of physical resource blocks occupied by the ECSS, i=0, 1,. . . , N−1, and N_(RB) is the system bandwidth.

With reference to the second possible implementation manner of theeighth aspect of the present invention, in a fourth possibleimplementation manner, the locations, determined by the processor, ofthe physical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,i)+offset)mod N _(RB)

where Y_(k-1,i) is a serial number of an i^(th) physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, offset may be avirtual cell ID or a subframe timeslot number, N is the number ofphysical resource blocks occupied by the ECSS, i=0, 1, . . . , N−1, andN_(RB) is the system bandwidth.

With reference to the eighth aspect of the present invention, in a fifthpossible implementation manner, the physical resources occupied by theECSS being random locations related to at least one of a physical orvirtual cell ID, a subframe timeslot number, and a system bandwidthincludes that:

each physical resource occupied by the ECSS is randomly generated;

alternatively, a first physical resource occupied by the ECSS israndomly generated.

With reference to the fifth possible implementation manner of the eighthaspect of the present invention, in a sixth possible implementationmanner, the locations, determined by the processor, of the physicalresources occupied by the ECSS are:

Y _(k,i)=((A _(i) ·Y _(k-1,i))mod D _(i))mod N _(RB)

where Y_(−1,i)=X, A_(i)=A+i*offset, A=3982, D_(i)=D+i*offset, D=65537,k=└n_(s)/2┘, n_(s) is a number of a timeslot in a subframe, X is avirtual cell ID, N is the number of physical resource blocks occupied bythe ECSS, i=0, 1, . . . , N−1, and N_(RB) is the system bandwidth.

With reference to the fifth possible implementation manner of the eighthaspect of the present invention, in a seventh possible implementationmanner, the first physical resource, determined by the processor,occupied by the ECSS is:

Y _(k)=((A·Y _(k-1))mod D)mod N _(RB)

where Y⁻¹=X, X is a virtual cell ID, A=39827, D=65537, k=└n_(s)/2┘,n_(s) is a number of a timeslot in a subframe, other physical resourcesoccupied by the ECSS are: (Y_(k)+└N_(RB)/N┘·i)mod N_(RB), N is thenumber of physical resource blocks occupied by the ECSS, i=0, 1, . . . ,N−1, and N_(RB) is the system bandwidth.

With reference to the eighth aspect of the present invention, in aneighth possible implementation manner, the physical resources occupiedby the ECSS being random locations related to at least one of a physicalor virtual cell ID, a subframe timeslot number, and a system bandwidthincludes that:

the whole system bandwidth is divided into N groups of predefinedresources not overlapping with each other, and physical resourcesoccupied by the ECSS of different cells in different subframes are arandom group, determined by a random function and related to at leastone of the physical or virtual cell ID, the subframe timeslot number,and the system bandwidth, among the resource groups.

With reference to the eighth possible implementation manner of theeighth aspect of the present invention, in a ninth possibleimplementation manner, the random function is a hash (Hash) function.

A ninth aspect of the present invention provides a base station, whichis used in a cross-carrier scheduling process, where an EPDCCH candidateon at least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The base station includes: an ECSS resourcedetermining device and a sending device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The sending device is configured to place the ECSS in a physicalresource, determined by the ECSS resource determining device, occupiedby the ECSS, and send a carrier in which the ECSS is placed.

A tenth aspect of the present invention provides a user equipment UE,which is used in a cross-carrier scheduling process, where an EPDCCHcandidate on at least two carriers is located in an EPDCCH resource seton one carrier among the at least two carriers, an aggregation level ofthe EPDCCH is L, and L>=1. The UE includes an ECSS resource determiningdevice and a receiving device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The receiving device is configured to detect the ECSS in a physicalresource, determined by the ECSS resource determining device, occupiedby the ECSS, and obtain common control information of a cell by means ofparsing.

In the EPDCCH candidate determining method provided by the embodiment ofthe present invention, during determination of an EPDCCH candidate usedto carry an EPDCCH, EPDCCH candidates of two carriers at the sameaggregation level are spaced by a candidate offset; as compared with atechnology in the prior art where EPDCCH candidates corresponding tocarriers at the same aggregation level completely overlap, EPDCCHcandidates of different carriers can be staggered, so that an EPDCCH ofeach carrier can be successfully placed in a corresponding EPDCCHcandidate, so as to prevent some EPDCCHs from being discarded due tooverlapping of the EPDCCH candidates, thereby avoiding EPDCCH blocking,and improving reliability of control information transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention art more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments.Apparently, the accompanying drawings in the following description showmerely some embodiments of the present invention, and a person ofordinary skill in the art may still derive other drawings from theseaccompanying drawings without creative efforts.

FIG. 1 is a flowchart of an EPDCCH candidate determining method in anembodiment of the present invention;

FIG. 2 is a flowchart of an EPDCCH candidate determining method inanother embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an EPDCCH candidatedetermining device in another embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an EPDCCH candidatedetermining device in another embodiment of the present invention;

FIG. 5 is a flowchart of an ECSS resource determining method in anotherembodiment of the present invention;

FIG. 6 is a schematic structural diagram of an ECSS resource determiningdevice in another embodiment of the present invention; and

FIG. 7 is a schematic structural diagram of an ECSS resource determiningdevice in another embodiment of the present invention.

DETAILED DESCRIPTION

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely a part rather than all of theembodiments of the present invention. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments of thepresent invention without creative efforts shall fall within theprotection scope of the present invention.

An embodiment of the present invention provides an EPDCCH candidatedetermining method, which is used in a cross-carrier scheduling process,where an EPDCCH candidate on at least two carriers is located in anEPDCCH resource set on one carrier among the at least two carriers, anaggregation level of the EPDCCH is L, and L>=1. As shown in FIG. 1, themethod includes:

101: Determine the EPDCCH resource set p in a subframe k, where theEPDCCH resource set p includes q resource block pairs, each of theresource block pairs corresponds to r enhanced control channel elementsECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×r indicates the number of ECCEs in theEPDCCH resource set p, reference numerals of the N_(ECCE,p,k) ECCEs are0, 1, 2, . . . , N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of theEPDCCH at the aggregation level L corresponds to L ECCEs havingconsecutive reference numerals, and an EPDCCH candidate is capable ofcarrying an EPDCCH.

Some resource sets among wireless transmission resources may be used totransmit an EPDCCH, and a method for determining the EPDCCH resource setp that can be used to transmit the EPDCCH belongs to the prior art, andis not described in detail in the embodiment of the present invention.The EPDCCH resource set p may be formed by multiple resource blockpairs. Specifically, in a subframe k, a pair of resource blocks(Resource Block, RB) of two timeslots is referred to as a resource blockpair (RB pair, RB pair). During actual sending, a resource block pairused by a physical resource is also referred to as a physical resourceblock pair (Physical RB pair, PRB pair). According to different types ofsubframes, in a PRB pair, 2 or 4 enhanced control channel elements(Enhanced Control Channel Element, ECCE) may exist. Specifically, a PRBpair has 16 enhanced resource element groups (Enhanced Resource ElementGroup, EREG), and numerals of the 16 EREGs are 0, 1, 2 . . . 15. For asubframe with a normal cyclic prefix, 4 EREGs form an ECCE, an in thisway, a PRB pair includes 4 ECCEs. For a subframe with an extended cyclicprefix, 8 EREGs form an ECCE, and therefore a PRB pair includes 2 ECCEs.

For example, as shown in Table 1, using an aggregation level 1 as anexample, an EPDCCH of a carrier has 4 EPDCCH candidates, the EPDCCHresource set has 16 potential EPDCCH candidates, which are ECCE0, ECCE1,ECCE2 . . . ECCE15 respectively, and 4 EPDCCH candidates fortransmitting the EPDCCH may be determined among the 16 potential EPDCCHcandidates. The number of EPDCCH candidates depends on an aggregationlevel L_(t) of a to-be-transmitted EPDCCH, and the numbers of EPDCCHcandidates corresponding to different aggregation levels are different,for example, the numbers of candidates corresponding to aggregationlevels 1, 2, 4, and 8 are 4, 6, 2, and 2.

TABLE 1 ECCE0 ECCE1 ECCE2 ECCE3 ECCE4 ECCE5 ECCE6 ECCE7 ECCE8 Carrier 1Candidate 1 Candidate 2 Candidate 3 Carrier 2 Candidate 1 Candidate 2Candidate 3 ECCE9 ECCE10 ECCE11 ECCE12 ECCE13 ECCE14 ECCE15 Carrier 1Candidate 4 Carrier 2 Candidate 4

Table 1 is a schematic diagram of EPDCCH candidate distribution of twocarriers—a carrier 1 (CA1) and a carrier 2 (CA2) in an EPDCCH resourceset is in Table 1. Aggregation levels of to-be-transmitted EPDCCHs ofthe two carriers are both L_(t), and therefore it is determined in theprior art that the EPDCCH candidates of CA1 and the EPDCCH candidates ofCA2 are distributed on same ECCEs, while an ECCE can only carry onePDCCH.

102: Determine the number of EPDCCH candidates at the aggregation levelL of a carrier corresponding to an index Cellindex and an ECCEcorresponding to each EPDCCH candidate, where the ECCE corresponding toeach EPDCCH candidate at the aggregation level L is related to the indexCellindex.

That the ECCE corresponding to each EPDCCH candidate at the aggregationlevel L is related to the index Cellindex indicates that the ECCEcorresponding to each EPDCCH candidate may be calculated according tothe index Cellindex and other related parameters, and a calculatingmethod may be adjusted according to actual needs.

In a first implementation manner of this embodiment, the determining thenumber of EPDCCH candidates at the aggregation level L of a carriercorresponding to an index Cellindex and an ECCE corresponding to eachEPDCCH candidate includes obtaining an ECCE corresponding to an m^(th)EPDCCH candidate according to the following formula:

$\begin{matrix}{{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i} & \left( {{Formula}\mspace{14mu} 1} \right)\end{matrix}$

where Y_(p,k) is a random value related to subframe number k and theEPDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of EPDCCH candidates, of the UE, corresponding to the aggregationlevel L of the EPDCCH resource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1,and n_(Cellindex) is a predefined candidate offset of the carriercorresponding to the index Cellindex.

For example, an example of Y_(p,k) is:

Y _(1,k) =Y _(0,k)+offset,Y _(0,k)=(A·Y _(0,k))mod D,Y _(0,-1) =n_(RNTI),

where p=0 or 1; n_(RNTI) is a radio network temporary identifier (RNTI,Radio Network Temporary Identifier) of the UE; offset is an integer, forexample 3, and is an offset value of Y_(p,k) of two EPDCCH sets;A=39827, D=65537, and k is the subframe number.

For example, another example of Y_(p,k) is:

Y _(p,k)=(A _(p) ·Y _(p,k-1))mod D,A ₀=39827,A ₁=39829,Y _(p,-1) =n_(RNTI) ,p=0 or 1

where the parameters have the same meaning as the foregoing parameters.The foregoing methods for generating Y_(p,k) are applicable to all theembodiments in this specification.

In this embodiment, n_(Cellindex) may be a relative offset of candidateshaving a same serial number between carriers corresponding to the indexCellindex. A value range of n_(Cellindex) may be from 0 to the number D1of carriers in carrier aggregation of the user equipment minus 1 or tothe number D2 of schedulable carriers of the user equipment in theEPDCCH set minus 1, where the schedulable carriers include carriersactivated and deactivated in the EPDCCH set p by the user equipment inthe subframe k.

In the first implementation manner, optionally, according to ascendingorder or descending order of the indexes Cellindex of the carriers, afirst serial number sequence, which is sequentially numbered, isobtained starting from 0, and n_(Cellindex) is a serial number value ofthe carrier index Cellindex in the first serial number sequence.

For example, as shown in Table 2, the index Cellindex may be a value ofa carrier indicator field (Carrier Indicator Field, CIF), and the CIF isconfigured by using higher layer signaling, and is used to identify adifferent carrier. It may be pre-configured on the base station or theUE that the relative offsets n_(Cellindex) of candidates having a sameserial number between carriers are serial numbers of the indexesCellindex sequenced in ascending order. The first serial number sequenceis in the form of 0, 1, 2 . . . , and a serial number interval is 1;therefore, locations of EPDCCH candidates of two carriers at the sameaggregation level are spaced by 1.

TABLE 2 ECCE0 ECCE1 ECCE2 ECCE3 ECCE4 ECCE5 ECCE6 ECCE7 ECCE8 Carrier 1Candidate 1 Candidate 2 Candidate 3 Carrier 2 Candidate 1 Candidate 2ECCE9 ECCE10 ECCE11 ECCE12 ECCE13 ECCE14 ECCE15 Carrier 1 Candidate 4Carrier 2 Candidate 3 Candidate 4

In Table 2, C=2, that is, the number of carriers required to bescheduled in cross-carrier scheduling is two, the two scheduled carriersare the carrier 1 and the carrier 2 respectively, a CIF value of thecarrier 1 is 1, and a CIF value of the carrier 2 is 6. According toascending order of the CIF, n_(Cellindex) of the carrier with CIF=1 is0, and n_(Cellindex) of the carrier with CIF=6 is 1. For example, acentralized EPDCCH set has 4 PRB pairs, each PRB pair has 4 ECCEs, theaggregation level L of the EPDCCH of the carrier 1 and the aggregationlevel L of the EPDCCH of the carrier 2 are both 1, and the numbers ofEPDCCH candidates of the two carriers are both 4. Y_(p,k) is assumed tobe 0; the first, second, third, and fourth EPDCCH candidates of thecarrier 1 are ECCE0, ECCE4, ECCE8, and ECCE12 respectively; and thefirst, second, third, and fourth EPDCCH candidates of the carrier 2 areECCE1, ECCE5, ECCE9, and ECCE13 respectively. In this way, although thenumbers of the EPDCCH candidates of the two carriers at the aggregationlevel are the same, the locations of the EPDCCH candidates distributedin the EPDCCH resource set do not overlap with each other, and theEPDCCH candidates of the carrier 1 are staggered from those of thecarrier 2; therefore, it can be ensured that when EPDCCHs of thecarriers are placed in the EPDCCH candidates, EPDCCH blocking is notcaused, and control information of the carrier 1 and the carrier 2 isprevented from being lost.

In the first implementation manner, optionally, n_(Cellindex) may be avalue of the index Cellindex.

For example, the index Cellindex of a carrier is further a CIF valuecorresponding to the carrier, the CIF value of the carrier 1 is 1, andthe CIF value of the carrier 2 is 6. Correspondingly, n_(Cellindex) ofthe carrier 1 may be 1, n_(Cellindex) of the carrier 2 may be 6, and inthis way, a relative offset between EPDCCH candidates of the twocarriers may also be implemented, thereby avoiding the problem thatEPDCCH candidates of carriers at the same aggregation level overlap witheach other.

In a second implementation manner of this embodiment, the determiningthe number of EPDCCH candidates at the aggregation level L of a carriercorresponding to an index Cellindex and an ECCE corresponding to eachEPDCCH candidate includes obtaining an ECCE corresponding to an m^(th)EPDCCH candidate according to the following formula:

$\begin{matrix}{{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + {n_{Cellindex}\left\lfloor \frac{N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor}} \right){mod}\left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i} & \left( {{Formula}\mspace{14mu} 2} \right)\end{matrix}$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of the UE, corresponding to the aggregation level Lof the EPDCCH resource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, n is thenumber of carriers, └ ┘ is a rounding down symbol, and

$\left\lfloor \frac{N_{{ECCE},p,k}}{L\; \bullet \; M_{p}^{(L)}\bullet \; n} \right\rfloor$

has the same meaning as floor

$\left( \frac{N_{{ECCE},p,k}}{L\; \bullet \; M_{p}^{(L)}\bullet \; n} \right)$

and indicates rounding down of

$\frac{N_{{ECCE},p,k}}{L\; \bullet \; M_{p}^{(L)}\bullet \; n}.$

Similar to that in the first implementation manner of this embodiment,may be serial numbers sequenced according to the values of the indexesCellindex in ascending order or in descending order, or n_(Cellindex)may be a value of the index Cellindex, or n_(Cellindex) may also be apredefined fixed value. Different from the first implementation mannerof this embodiment, n_(Cellindex) is multiplied by a coefficient

$\left\lfloor \frac{N_{{ECCE},p,k}}{L\; \bullet \; M_{p}^{(L)}\bullet \; n} \right\rfloor,$

so that the EPDCCH candidates of the carriers can be distributed on thewhole frequency bandwidth of the EPDCCH resource set.

n_(Cellindex) is a relative offset, which is related to the indexCellindex, of candidates having a same serial number between carriers. Avalue range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the schedulable carriers include carriers activated and deactivatedin the EPDCCH set p by the user equipment in the subframe k.

Here, n may be obtained by using the following methods: n is the numberQ of the carriers of the user equipment, or n is the number ofschedulable carriers, of the user equipment, in the EPDCCH set p, wherethe schedulable carriers include carriers activated and deactivated inthe EPDCCH set p by the user equipment in the subframe k. Specifically,according to the number Q of the carriers of the user equipment and acarrier scheduling indication value, configured by a system, of each ofthe carriers, the number n of carriers, among scheduled carrierscorresponding to the EPDCCH set, scheduled by the user equipment isobtained; or, n is the number Q of carriers of in carrier aggregation ofthe user equipment. Assuming that the number of carriers in carrieraggregation of the user equipment is Q, on a certain carrier among the Qcarriers, control information of this carrier and other carriers isscheduled; and the system activates or deactivates the Q carriers byusing MAC signaling. For a deactivated carrier, the UE does not receiveor send data on the carrier, and the base station does not receive orsend the data of the UE on the carrier either. Meanwhile, the UE doesnot receive the EPDCCH for the carrier, and the base station does notsend the EPDCCH for the carrier to the UE either. For an activatedcarrier, the UE receives and sends data on the carrier, and the basestation receives and sends the data of the UE on the carrier. Meanwhile,the UE receives the EPDCCH for the carrier, and the base station alsosends the EPDCCH for the carrier to the UE.

TABLE 3 ECCE0 ECCE1 ECCE2 ECCE3 ECCE4 ECCE5 ECCE6 ECCE7 ECCE8 Carrier 1Candidate 1 Candidate 2 Candidate 3 Carrier 2 Candidate 1 Candidate 2ECCE9 ECCE10 ECCE11 ECCE12 ECCE13 ECCE14 ECCE15 Carrier 1 Candidate 4Carrier 2 Candidate 3 Candidate 4

For example, as shown in Table 3, an EPDCCH resource set has 4 PRBpairs, EPDCCHs of 2 carriers are carried in the EPDCCH resource set, andcross-carrier scheduling is performed on the carrier 1 and the carrier2. Aggregation levels of the EPDCCHs of the carrier 1 and the carrier 2are both 1; the EPDCCHs of the two carriers have 4 candidate resourceseach; Y_(p,k) is assumed to be 0; the first, second, third, and fourthcandidate resources of the carrier 1 are ECCE0, ECCE4, ECCE8, and ECCE12respectively; and the first, second, third, and fourth candidateresources of the carrier 2 are ECCE2, ECCE6, ECCE10, and ECCE14respectively. In this way, although the numbers of the candidateresources of the EPDCCHs of the two carriers at the same aggregationlevel are the same, the locations of the candidate resources distributedin the EPDCCH resource set do not overlap with each other, adjacentcandidate resources in the total 8 candidate resources of the twocarriers may be spaced by equal intervals, and the candidate resourcesof the two carriers are distributed in the EPDCCH resource set in adispersed manner; therefore, EPDCCH blocking can be avoided, andmoreover, the candidate resources are distributed on the whole frequencybandwidth as evenly as possible, so that a gain of selective schedulingof frequency is obtained, and the reliability of EPDCCH transmission isenhanced.

In a third implementation manner of this embodiment, the determining thenumber of EPDCCH candidates at the aggregation level L of a carriercorresponding to an index Cellindex and an ECCE corresponding to eachEPDCCH candidate includes obtaining an ECCE corresponding to an m^(th)EPDCCH candidate according to the following formula:

$\begin{matrix}{{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m^{\prime} \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i} & \left( {{Formula}\mspace{14mu} 3} \right)\end{matrix}$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of the UE, corresponding to the aggregation level Lof the EPDCCH resource set p, 0<=i<=L−1, 0<m<=M_(p) ^((L))−1m′=m·n+n_(Cellindex), n is the number of carriers, and “·” has the samemeaning as “x” and indicates multiplying.

n_(Cellindex) is a relative offset, which is related to the indexCellindex, of candidates having a same serial number between carriers. Avalue range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the schedulable carriers include carriers activated and deactivatedin the EPDCCH set p by the user equipment in the subframe k.

n is the number Q of the carriers of the user equipment, or n is thenumber of schedulable carriers of the user equipment in the EPDCCH setp, where the schedulable carriers include carriers activated anddeactivated in the EPDCCH set p by the user equipment in the subframe k.

Further, locations of EPDCCH candidates having a serial number indifferent carriers may be allocated in a resource block pair as far aspossible. Specifically, carriers may be sequenced and numbered accordingto CIF values, to obtain the index Cellindex of each carrier, and if anEPDCCH candidate, whose serial number is k, at the aggregation level Lof the carrier corresponding to the index Cellindex is at a relativelyrear location in a resource block pair, candidate offsets of EPDCCHcandidates, whose serial numbers are k, of other carriers at the sameaggregation level L with the carrier have negative signs.

Specifically, an EPDCCH resource set has q PRB pairs, the number ofECCEs in a PRB pair is r, and the aggregation levels L of the carrier 1may be 1, 2, 4, 8, 16, or 32 and so on. When r>L, at the aggregationlevel L, a PRB pair may have q×r/L potential EPDCCH candidates. Apotential EPDCCH candidate indicates that the potential EPDCCH candidatemay be selected as an EPDCCH candidate, and an EPDCCH candidate cancarry an EPDCCH at the aggregation level L.

TABLE 4 ECCE0 ECCE1 ECCE2 ECCE3 ECCE4 ECCE5 ECCE6 ECCE7 ECCE8 Carrier 1Candidate 1 Candidate 2 Carrier 2 Candidate 1 Candidate 2 ECCE9 ECCE10ECCE11 ECCE12 ECCE13 ECCE14 ECCE15 Carrier 1 Candidate 3 Candidate 4Carrier 2 Candidate 3 Candidate 4

For example, as shown in Table 4, ECCE0-ECCE3 belong to a first PRBpair, ECCE4-ECCE7 belong to a second PRB pair, ECCE8-ECCE11 belong to athird PRB pair, and ECCE12-ECCE15 belong to a fourth PRB pair. Thecarrier 1 and the carrier 2 have the same aggregation level; if anEPDCCH candidate, whose serial number is i, corresponding to an EPDCCHof the carrier 1 is on first q×r/L/2 potential EPDCCH candidates of aPRB pair, a location of an i^(th) EPDCCH candidate of the carrier 2 anda location of an i^(th) EPDCCH candidate of the carrier 1 are spaced bya candidate offset of +1; if an EPDCCH candidate, whose serial number isi, corresponding to an EPDCCH of the carrier 1 is on last q×r/L/2potential EPDCCH candidates of a PRB pair, a location of an i^(th)EPDCCH candidate of the carrier 2 and a location of an i^(th) EPDCCHcandidate of the carrier 1 are spaced by a candidate offset of −1.

In the EPDCCH candidate determining method provided by the embodiment ofthe present invention, during determination of an EPDCCH candidate usedto carry an EPDCCH, EPDCCH candidates of two carriers at the sameaggregation level are spaced by a candidate offset; as compared with atechnology in the prior art where EPDCCH candidates corresponding tocarriers at the same aggregation level completely overlap, EPDCCHcandidates of different carriers can be staggered, so that an EPDCCH ofeach carrier can be successfully placed in a corresponding EPDCCHcandidate, so as to prevent some EPDCCHs from being discarded due tooverlapping of the EPDCCH candidates, thereby avoiding EPDCCH blocking,and improving reliability of control information transmission.

To make a person skilled in the art understand and apply the method ofthe present invention, another embodiment of the present inventionprovides an application embodiment, on a base station side, of an EPDCCHcandidate determining method. This embodiment is used to send an EPDCCHof multiple carriers to a user equipment UE on an EPDCCH resource set ofa carrier, and the UE may receive an EPDCCH of multiple carriers on anEPDCCH resource set. As shown in FIG. 2, the method of this embodimentincludes:

201: A base station determines the EPDCCH resource set p in a subframek, where the EPDCCH resource set p includes q resource block pairs, eachof the resource block pairs corresponds to r enhanced control channelelements ECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×r indicates the number ofECCEs in the EPDCCH resource set p, reference numerals of theN_(ECCE,p,k) ECCEs are 0, 1, 2, . . . , N_(ECCE,p,k)−1 respectively, anEPDCCH candidate of the EPDCCH at an aggregation level L corresponds toL ECCEs having consecutive reference numerals, and an EPDCCH candidateis capable of carrying an EPDCCH.

202: The base station determines the number of EPDCCH candidates at theaggregation level L of a carrier corresponding to an index Cellindex andan ECCE corresponding to each EPDCCH candidate, where the ECCEcorresponding to each EPDCCH candidate at the aggregation level L isrelated to the index Cellindex.

203: The base station places a to-be-transmitted EPDCCH of the carriercorresponding to the index Cellindex in an EPDCCH candidate amongmultiple determined EPDCCH candidates, and sends the EPDCCH.

The to-be-transmitted EPDCCH is placed in an EPDCCH candidate amongmultiple EPDCCH candidates at the aggregation level L of the carriercorresponding to the index Cellindex, and sent to a UE. In this way, theUE may determine, by using different aggregation levels, an EPDCCHcandidate corresponding to each aggregation level, and detects theto-be-transmitted EPDCCH in the determined EPDCCH candidates. When theUE detects a correct EPDCCH, the UE obtains control information of at^(th) carrier from the correct EPDCCH by means of parsing; when the UEfails to detect a correct EPDCCH, the UE continues to determine, byusing another aggregation level, a corresponding EPDCCH candidate, andperforms detection until a correct EPDCCH is detected or the q×r ECCEsare traversed.

204: The UE determines the EPDCCH resource set p in the subframe k,where the EPDCCH resource set p includes q resource block pairs, each ofthe resource block pairs corresponds to r enhanced control channelelements ECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×r indicates the number ofECCEs in the EPDCCH resource set p, reference numerals of theN_(ECCE,p,k) ECCEs are 0, 1, 2, . . . , N_(ECCE,p,k)−1 respectively, anEPDCCH candidate of the EPDCCH at the aggregation level L corresponds toL ECCEs having consecutive reference numerals, and an EPDCCH candidateis capable of carrying an EPDCCH.

205: The UE determines the number of EPDCCH candidates at theaggregation level L of a carrier corresponding to an index Cellindex andan ECCE corresponding to each EPDCCH candidate, where the ECCEcorresponding to each EPDCCH candidate at the aggregation level L isrelated to the index Cellindex.

206: The UE detects the determined EPDCCH candidate corresponding to theaggregation level L of the carrier corresponding to the index Cellindex;when a correct EPDCCH is detected, the UE obtains control information ofthe carrier corresponding to the index Cellindex from the correct EPDCCHby means of parsing; when no correct EPDCCH is detected, by usinganother aggregation level, and the UE continues to determine the EPDCCHcandidate corresponding to the aggregation level L of the carriercorresponding to the index Cellindex and performs detection until acorrect EPDCCH is detected or the q×r ECCEs are traversed.

It should be noted that, for detailed descriptions of some steps in theembodiment of the present invention, reference may be made to thecontent in the embodiment corresponding to FIG. 1, which is notrepeatedly described in detail in the embodiment of the presentinvention.

In the EPDCCH candidate determining method provided by the embodiment ofthe present invention, during determination of a candidate resource usedto carry an EPDCCH, candidate resources of two carriers at the sameaggregation level are spaced by a candidate offset; as compared with atechnology in the prior art where candidate resources corresponding tocarriers at the same aggregation level completely overlap, candidateresources of different carriers can be staggered, so that an EPDCCH ofeach carrier can be successfully placed in a corresponding candidateresource, so as to prevent some EPDCCHs from being discarded due tooverlapping of the candidate resources, thereby avoiding EPDCCHblocking, and improving reliability of control information transmission.

Another embodiment of the present invention provides an EPDCCH candidatedetermining device, which is used in a cross-carrier scheduling process,where an EPDCCH candidate on at least two carriers is located in anEPDCCH resource set on one carrier among the at least two carriers, anaggregation level of the EPDCCH is L, and L>=1. As shown in FIG. 3, thedevice includes:

a first determining unit 31, configured to determine the EPDCCH resourceset p in a subframe k, where the EPDCCH resource set p includes qresource block pairs, each of the resource block pairs corresponds to renhanced control channel elements ECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×rindicates the number of ECCEs in the EPDCCH resource set p, referencenumerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . , N_(ECCE,p,k)−1respectively, an EPDCCH candidate of the EPDCCH at the aggregation levelL corresponds to L ECCEs having consecutive reference numerals, and anEPDCCH candidate is capable of carrying an EPDCCH; and

a second determining unit 32, configured to determine the number ofEPDCCH candidates at the aggregation level L of a carrier correspondingto an index Cellindex and an ECCE corresponding to each EPDCCH candidatein the EPDCCH resource set p determined by the first determining unit31, where the ECCE corresponding to each EPDCCH candidate at theaggregation level L is related to the index Cellindex.

Further optionally, the second determining unit 32 is further configuredto obtain an ECCE corresponding to an m^(th) EPDCCH candidate accordingto the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and theEPDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of EPDCCH candidates, of a user equipment UE corresponding to theEPDCCH candidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.

Further optionally, the second determining unit 32 is further configuredto obtain an ECCE corresponding to an m^(th) EPDCCH candidate accordingto the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + {n_{Cellindex}\left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n is the number ofcarriers.

Further optionally, the second determining unit 32 is further configuredto obtain an ECCE corresponding to an m^(th) EPDCCH candidate accordingto the following formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m^{\prime} \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, m′=m·n+n_(Cellindex),and n is the number of carriers.

Further, n is the number Q of carriers of the user equipment, or

n is the number of schedulable carriers of the user equipment in theEPDCCH set p, including carriers activated and deactivated in the EPDCCHset p by the user equipment in the subframe k.

Further optionally, n_(Cellindex) is a relative offset, which is relatedto the index Cellindex, of candidates having a same serial numberbetween carriers.

A value range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the D2 schedulable carriers includes carriers activated anddeactivated in the EPDCCH set p by the user equipment in the subframe k.

Further optionally, according to ascending order or descending order ofthe indexes Cellindex of the carriers, a first serial number sequence,which is sequentially numbered, is obtained starting from 0, andn_(Cellindex) is a serial number value of the carrier index Cellindex inthe first serial number sequence.

Further optionally, n_(Cellindex) is a value of the index Cellindex.

In the EPDCCH candidate determining device provided by the embodiment ofthe present invention, during determination of a candidate resource usedto carry an EPDCCH, candidate resources of two carriers at the sameaggregation level are spaced by a candidate offset; as compared with atechnology in the prior art where candidate resources corresponding tocarriers at the same aggregation level completely overlap, candidateresources of different carriers can be staggered, so that an EPDCCH ofeach carrier can be successfully placed in a corresponding candidateresource, so as to prevent some EPDCCHs from being discarded due tooverlapping of the candidate resources, thereby avoiding EPDCCHblocking, and improving reliability of control information transmission.

Another embodiment of the present invention provides an EPDCCH candidatedetermining device, which is used in a cross-carrier scheduling process,where an EPDCCH candidate on at least two carriers is located in anEPDCCH resource set on one carrier among the at least two carriers, anaggregation level of the EPDCCH is L, and L>=1. As shown in FIG. 4, thedevice includes:

a memory 41, configured to store program code used to determine anEPDCCH candidate; and

a processor 42, configured to read and run the program code stored inthe memory 41, where the program code is used to execute the followingoperations: determining the EPDCCH resource set p in a subframe k, wherethe EPDCCH resource set p includes q resource block pairs, each of theresource block pairs corresponds to r enhanced control channel elementsECCEs, q>=1, r>=1, N_(ECCE,p,k)=q×r indicates the number of ECCEs in theEPDCCH resource set p, reference numerals of the N_(ECCE,p,k) ECCEs are0, 1, 2, . . . , N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of theEPDCCH at the aggregation level L corresponds to L ECCEs havingconsecutive reference numerals, and an EPDCCH candidate is capable ofcarrying an EPDCCH; and

determining the number of EPDCCH candidates at the aggregation level Lof a carrier corresponding to an index Cellindex and an ECCEcorresponding to each EPDCCH candidate, where the ECCE corresponding toeach EPDCCH candidate at the aggregation level L is related to the indexCellindex.

Further optionally, the determining the number of EPDCCH candidates atthe aggregation level L of a carrier corresponding to an index Cellindexand an ECCE corresponding to each EPDCCH candidate includes obtaining anECCE corresponding to an m^(th) EPDCCH candidate according to thefollowing formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and theEPDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of EPDCCH candidates, of a user equipment UE corresponding to theEPDCCH candidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.

Further optionally, the determining the number of EPDCCH candidates atthe aggregation level L of a carrier corresponding to an index Cellindexand an ECCE corresponding to each EPDCCH candidate includes obtaining anECCE corresponding to an m^(th) EPDCCH candidate according to thefollowing formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + {n_{Cellindex}\left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n is the number ofcarriers.

Further optionally, the determining the number of EPDCCH candidates atthe aggregation level L of a carrier corresponding to an index Cellindexand an ECCE corresponding to each EPDCCH candidate includes obtaining anECCE corresponding to an m^(th) EPDCCH candidate according to thefollowing formula:

${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m^{\prime} \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)} \cdot n} \right\rfloor} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$

where Y_(p,k) is a random value related to subframe number k and EPDCCHset index p, p and k are both integers, M_(p) ^((L)) is the number ofEPDCCH candidates, of a user equipment UE corresponding to the EPDCCHcandidate, corresponding to the aggregation level L of the EPDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, m′=m·n+n_(Cellindex),and n is the number of carriers.

Further optionally, n is the number Q of carriers of the user equipment,or

n is the number of schedulable carriers of the user equipment in theEPDCCH set p, including carriers activated and deactivated in the EPDCCHset p by the user equipment in the subframe k.

Further optionally, n_(Cellindex) is a relative offset, which is relatedto the index Cellindex, of candidates having a same serial numberbetween carriers.

A value range of n_(Cellindex) is from 0 to the number D1 of carriers incarrier aggregation of the user equipment minus 1 or to the number D2 ofschedulable carriers of the user equipment in the EPDCCH set minus 1,and the D2 schedulable carriers includes carriers activated anddeactivated in the EPDCCH set p by the user equipment in the subframe k.

Further optionally, according to ascending order or descending order ofthe indexes Cellindex of the carriers, a first serial number sequence,which is sequentially numbered, is obtained starting from 0, andn_(Cellindex) is a serial number value of the carrier index Cellindex inthe first serial number sequence.

Further optionally, n_(Cellindex) is a value of the index Cellindex.

In the EPDCCH candidate determining device provided by the embodiment ofthe present invention, during determination of a candidate resource usedto carry an EPDCCH, candidate resources of two carriers at the sameaggregation level are spaced by a candidate offset; as compared with atechnology in the prior art where candidate resources corresponding tocarriers at the same aggregation level completely overlap, candidateresources of different carriers can be staggered, so that an EPDCCH ofeach carrier can be successfully placed in a corresponding candidateresource, so as to prevent some EPDCCHs from being discarded due tooverlapping of the candidate resources, thereby avoiding EPDCCHblocking, and improving reliability of control information transmission.

Another embodiment of the present invention provides a base station,which is used in a cross-carrier scheduling process, where an EPDCCHcandidate on at least two carriers is located in an EPDCCH resource seton one carrier among the at least two carriers, an aggregation level ofthe EPDCCH is L, and L>=1. The base station includes the EPDCCHcandidate determining device shown in FIG. 3 or FIG. 4, and a sendingdevice.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The sending device is configured to place an EPDCCH of a carrier, whoseindex Cellindex is a carrier indicator field index Cellindex, in oneEPDCCH candidate among EPDCCH candidates determined by the EPDCCHcandidate determining device, and send the EPDCCH.

An embodiment of the present invention further provides a UE, which isused in a cross-carrier scheduling process, where an EPDCCH candidate onat least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The UE includes an EPDCCH candidate determiningdevice and a receiving device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The receiving device is configured to detect the EPDCCH candidatedetermined by the EPDCCH candidate determining device; when a correctEPDCCH is detected, obtain control information of the carrier, whoseindex Cellindex is a carrier indicator field index Cellindex, from thecorrect EPDCCH by means of parsing; and when no correct EPDCCH isdetected, instruct the EPDCCH candidate determining device to continueto determine, by using another aggregation level, the number of EPDCCHcandidates at the another aggregation level of the carrier correspondingto the index Cellindex and an ECCE corresponding to each EPDCCHcandidate until a correct EPDCCH is detected or the q×r ECCEs aretraversed.

An embodiment of the present invention further provides an EPDCCHtransmission system, which includes the foregoing base station and UE inthis embodiment.

In the UE, the base station, and the EPDCCH transmission system providedby the embodiments of the present invention, during determination of acandidate resource used to carry an EPDCCH, candidate resources of twocarriers at the same aggregation level are spaced by a candidate offset;as compared with a technology in the prior art where candidate resourcescorresponding to carriers at the same aggregation level completelyoverlap, candidate resources of different carriers can be staggered, sothat an EPDCCH of each carrier can be successfully placed in acorresponding candidate resource, so as to prevent some EPDCCHs frombeing discarded due to overlapping of the candidate resources, therebyavoiding EPDCCH blocking, and improving reliability of controlinformation transmission.

Another embodiment of the present invention provides an ECSS resourcedetermining method, which, as shown in FIG. 5, includes:

501: Configure, by using higher layer signaling, or determine, accordingto a predetermined rule, the number N of physical resources occupied bythe ECSS.

The determining, according to a predetermined rule, the number of thephysical resources occupied by the ECSS includes that: the number N ofphysical resources occupied by the ECSS is related to a systembandwidth. For example, the whole system bandwidth N_(RB) is dividedinto └N_(RB)/N┘ groups according to the number N of physical resourceblock pairs occupied by the ECSS. The number N of physical resourceblock pairs included in each group depends on the system bandwidth ofcurrent transmission, for example, when the system bandwidth N_(RB) isequal to 6, N=2; when the system bandwidth N_(RB) is greater than 6 andless than or equal to 25, N=4; in other cases, N=8.

The ECSS may be used for an EPDCCH of common control information, arandom access response (RAR), or a multicast TPC Command, and so on.

502: Determine locations of the physical resources occupied by the ECSS,where the locations of the physical resources occupied by the ECSS arepredefined locations related to at least one of a physical cell ID, avirtual cell ID, a subframe timeslot number, and a system bandwidth, orrandom locations related to at least one of a physical or virtual cellID, a subframe timeslot number, and a system bandwidth.

In a first implementation manner of this embodiment, the locations ofthe physical resources occupied by the ECSS are predefined locationsrelated to at least one of the physical cell ID, the virtual cell ID,the subframe timeslot number, and the system bandwidth.

The locations of the physical resources occupied by the ECSS beingpredefined locations related to at least one of a physical cell ID, avirtual cell ID, a subframe timeslot number, and a system bandwidthincludes that: a fixed deviation exists between physical resource blocksoccupied by an ECSS of each cell, and under different subframe timeslotnumbers or different physical or virtual cell IDs, physical resourceblocks occupied by an ECSS are different.

Further optionally, the locations of the physical resources occupied bythe ECSS are:

Y _(k,i)=(Y _(k-1,0) +X)mod N _(RB)+(└N _(RB) /N┘)*i

where Y_(k-1,0) is a serial number of a first physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, Y_(−1,0) is apredefined value being the same for all cells, X is a virtual cell ID, Nis the number of physical resource blocks occupied by the ECSS, i=0, 1,. . . , N−1, and N_(RB) is the system bandwidth.

Further optionally, the locations of the physical resources occupied bythe ECSS are:

Y _(k,i)=(Y _(k-1,i)+offset)mod N _(RB)

where Y_(k-1,i) is a serial number of an i^(th) physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, offset may be avirtual cell ID or a subframe timeslot number, N is the number ofphysical resource blocks occupied by the ECSS, i=0, 1, . . . , N−1, andN_(RB) is the system bandwidth.

In a second possible implementation manner, the locations of thephysical resources occupied by the ECSS are random locations related toat least one of the physical or virtual cell ID, the subframe timeslotnumber, and the system bandwidth.

Each physical resource occupied by the ECSS is randomly generated.Alternatively, a first physical resource occupied by the ECSS israndomly generated.

Further optionally, the locations of the physical resources occupied bythe ECSS are:

Y _(k,i)=((A _(i) ·Y _(k-1,i))mod D _(i))mod N _(RB)

where i=0, 1, . . . , N−1, Y_(−1,i)=X, A_(i)=A+i*offset, A=39827,D_(i)=D+i*offset, D=65537, k=└n_(s)/2┘, n_(s) is a number of a timeslotin a subframe, X is a virtual cell ID, N is the number of physicalresource blocks occupied by the ECSS, i=0, 1, . . . , N−1, and N_(RB) isthe system bandwidth. Selection of the location of each physicalresource block pair of the ECSS is determined by a cell-specific randomfunction dynamically changeable for each subframe, such as a hashfunction, that is, each physical resource block pair of the ECSS isdetermined by a random function, and each subframe is dynamicallychangeable.

Further optionally, a cell-specific random function, such as a hashfunction, randomly determines a starting location of physical resourceblock pairs of an ECSS, and selection is performed at equal intervalswith reference to Scheme 1. The first physical resource occupied by theECSS is:

Y _(k)=((A·Y _(k-1))mod D)mod N _(RB)

where Y⁻¹=X, X is a virtual cell ID, A=39827, D=65537, k=└n_(s)/2┘, ,n_(s) is a number of a timeslot in a subframe, other physical resourcesoccupied by the ECSS are: (Y_(k)+└N_(RB)/N┘·i)mod N_(RB), N is thenumber of physical resource blocks occupied by the ECSS, i=0, 1, . . . ,N−1, and N_(RB) is the system bandwidth.

In a third implementation manner of this embodiment, the physicalresources occupied by the ECSS being random locations related to atleast one of a physical or virtual cell ID, a subframe timeslot number,and a system bandwidth includes that: the whole system bandwidth isdivided into N predefined resource groups not overlapping with eachother, the resource group may be formed by one or more physical resourceblock pairs, and physical resources occupied by the ECSS of differentcells in different subframes are a random group, determined by therandom function and related to at least one of the physical or virtualcell ID, the subframe timeslot number, and the system bandwidth, amongthe resource groups.

N physical resource block pairs of each group meet the followingrelationship: the whole system bandwidth is traversed; when selection isperformed according to a maximum interval, and when the system bandwidthN_(RB) cannot be exactly divided by the number N of the physicalresource block pairs occupied by the ECSS, a rounded-up or rounded-downvalue of N_(RB)/n is selected as the maximum interval. Further, therandom function may be a hash (Hash) function.

In the ECSS resource determining method provided by the embodiment ofthe present invention, for an ECCS for transmitting common controlinformation, physical resources of the ECCS are allocated reasonably,but no method relating to reasonable allocation of physical resourcesoccupied by an ECCS is available in the prior art; therefore, theembodiment of the present invention eliminates a blind area in design,achieves inter-cell interference coordination and a frequency domaindiversity gain, and improves transmission reliability of common controlinformation of an EPDCCH.

Another embodiment of the present invention further provides an ECSSresource determining device, which, as shown in FIG. 6, includes:

a third determining unit 61, adapted to configure, by using higher layersignaling, or determine, according to a predetermined rule, the number Nof physical resources occupied by the ECSS; and

a fourth determining unit 62, configured to determine, according to thenumber N, determined by the third determining unit 61, of physicalresources occupied by the ECSS, locations of the physical resourcesoccupied by the ECSS, where the locations of the physical resourcesoccupied by the ECSS are predefined locations related to at least one ofa physical or virtual cell ID, a subframe timeslot number, and a systembandwidth, or random locations related to at least one of a physical orvirtual cell ID, a subframe timeslot number, and a system bandwidth.

Further optionally, the number N of the physical resources occupied bythe ECSS is related to the system bandwidth.

Further optionally, the locations of the physical resources occupied bythe ECSS being predefined locations related to at least one of aphysical cell ID, a virtual cell ID, a subframe timeslot number, and asystem bandwidth includes that:

a fixed deviation exists between physical resource blocks occupied by anECSS of each cell, and under different subframe timeslot numbers ordifferent physical or virtual cell IDs, physical resource blocksoccupied by an ECSS are different.

Further optionally, the locations, determined by the fourth determiningunit 62, of the physical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,0) +X)mod N _(RB)+(└N _(RB) /N┘)*i

where Y_(k-1,0) is a serial number of a first physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, Y_(−1,0) is apredefined value being the same for all cells, X is a virtual cell ID, Nis the number of physical resource blocks occupied by the ECSS, i=0, 1,. . . , N−1, and N_(RB) is the system bandwidth.

Further optionally, the locations, determined by the fourth determiningunit 62, of the physical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,i)+offset)mod N _(RB)

where Y_(k-1,i) is a serial number of an i^(th) physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, offset may be avirtual cell ID or a subframe timeslot number, N is the number ofphysical resource blocks occupied by the ECSS, i=0, 1, . . . , N−1, andN_(RB) is the system bandwidth.

Further optionally, the physical resources occupied by the ECSS beingrandom locations related to at least one of a physical or virtual cellID, a subframe timeslot number, and a system bandwidth includes that:

each physical resource occupied by the ECSS is randomly generated;

alternatively, a first physical resource occupied by the ECSS israndomly generated.

Further optionally, the locations, determined by the fourth determiningunit 62, of the physical resources occupied by the ECSS are:

Y _(k,i)=((A _(i) ·Y _(k-1,i))mod D _(i))mod N _(RB)

where Y_(−1,i)=X, A_(i)=A+i*offset, A=39827, D_(i)=D+i*offset, D=65537,k=└n_(s)/2┘, n_(s) is a number of a timeslot in a subframe, X is avirtual cell ID, N is the number of physical resource blocks occupied bythe ECSS, i=0, 1, . . . , N−1, and N_(RB) is the system bandwidth.

Further optionally, the first physical resource, determined by thefourth determining unit 62, occupied by the ECSS is:

Y _(k)=((A·Y _(k-1))mod D)mod N _(RB)

where Y⁻¹=X, X is a virtual cell ID, A=39827, D=65537, k=└n_(s)/2┘,n_(s) is a number of a timeslot in a subframe, other physical resourcesoccupied by the ECSS are: (Y_(k)+└N_(RB)/N┘·i)mod N_(RB), N is thenumber of physical resource blocks occupied by the ECSS, i=0, 1, . . . ,N−1, and N_(RB) is the system bandwidth.

Further optionally, the physical resources occupied by the ECSS beingrandom locations related to at least one of a physical or virtual cellID, a subframe timeslot number, and a system bandwidth includes that:

the whole system bandwidth is divided into N groups of predefinedresources not overlapping with each other, and physical resourcesoccupied by the ECSS of different cells in different subframes are arandom group, determined by a random function and related to at leastone of the physical or virtual cell ID, the subframe timeslot number,and the system bandwidth, among the resource groups.

Further optionally, the random function is a hash (Hash) function.

In the ECSS resource determining device provided by the embodiment ofthe present invention, for an ECCS for transmitting common controlinformation, physical resources of the ECCS are allocated reasonably,but no method relating to reasonable allocation of physical resourcesoccupied by an ECCS is available in the prior art; therefore, theembodiment of the present invention eliminates a blind area in design,achieves inter-cell interference coordination and a frequency domaindiversity gain, and improves transmission reliability of common controlinformation of an EPDCCH.

Another embodiment of the present invention further provides an ECSSresource determining device, which, as shown in FIG. 7, includes:

a memory 71, configured to store program code used to determine an ECSSresource; and

a processor 72, configured to read and run the program code stored inthe memory 71, where the program code is used to execute the followingoperations: configuring, by using higher layer signaling, ordetermining, according to a predetermined rule, the number N of physicalresources occupied by the ECSS; and

determining locations of the physical resources occupied by the ECSS,where the locations of the physical resources occupied by the ECSS arepredefined locations related to at least one of a physical or virtualcell ID, a subframe timeslot number, and a system bandwidth, or randomlocations related to at least one of a physical or virtual cell ID, asubframe timeslot number, and a system bandwidth.

Further optionally, the number N of the physical resources occupied bythe ECSS is related to the system bandwidth.

Further optionally, the locations of the physical resources occupied bythe ECSS being predefined locations related to at least one of aphysical cell ID, a virtual cell ID, a subframe timeslot number, and asystem bandwidth includes that:

a fixed deviation exists between physical resource blocks occupied by anECSS of each cell, and under different subframe timeslot numbers ordifferent physical or virtual cell IDs, physical resource blocksoccupied by an ECSS are different.

Further optionally, the locations, determined by the processor, of thephysical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,0) +X)mod N _(RB)+(└N _(RB) /N┘)*i

where Y_(k-1,0) is a serial number of a first physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, Y_(−1,0) is apredefined value being the same for all cells, X is a virtual cell ID, Nis the number of physical resource blocks occupied by the ECSS, i=0, 1,. . . , N−1, and N_(RB) is the system bandwidth.

Further optionally, the locations, determined by the processor, of thephysical resources occupied by the ECSS are:

Y _(k,i)=(Y _(k-1,i)+offset)mod N _(RB)

where Y_(k-1,i) is a serial number of an i^(th) physical resource blockpair occupied by an ECSS of a (k−1)^(th) subframe, offset may be avirtual cell ID or a subframe timeslot number, N is the number ofphysical resource blocks occupied by the ECSS, i=0, 1, . . . , N−1, andN_(RB) is the system bandwidth.

Further optionally, the physical resources occupied by the ECSS beingrandom locations related to at least one of a physical or virtual cellID, a subframe timeslot number, a system bandwidth includes that:

each physical resource occupied by the ECSS is randomly generated;

alternatively, a first physical resource occupied by the ECSS israndomly generated.

Further optionally, the locations, determined by the processor, of thephysical resources occupied by the ECSS are:

Y _(k,i)=((A _(i) ·Y _(k-1,i))mod D _(i))mod N _(RB)

where Y_(−1,i)=X, A_(i)=A+i*offset, A=39827, D_(i)=D+i*offset, D=65537,k=└n_(s)/2┘, n_(s) is a number of a timeslot in a subframe, X is avirtual cell ID, N is the number of physical resource blocks occupied bythe ECSS, i=0, 1, . . . , N−1, and N_(RB) is the system bandwidth.

Further optionally, the first physical resource, determined by theprocessor, occupied by the ECSS is:

Y _(k)=((A·Y _(k-1))mod D)mod N _(RB)

where Y⁻¹=X, X is a virtual cell ID, A=39827, D=65537, k=└n_(s)/2┘,n_(s) is a number of a timeslot in a subframe, other physical resourcesoccupied by the ECSS are: (Y_(k)+└N_(RB)/N┘·i)mod N_(RB), N is thenumber of physical resource blocks occupied by the ECSS, i=0, 1, . . . ,N−1, and N_(RB) is the system bandwidth.

Further optionally, the physical resources occupied by the ECSS beingrandom locations related to at least one of a physical or virtual cellID, a subframe timeslot number, and a system bandwidth includes that:

the whole system bandwidth is divided into N groups of predefinedresources not overlapping with each other, and physical resourcesoccupied by the ECSS of different cells in different subframes are arandom group, determined by a random function and related to at leastone of the physical or virtual cell ID, the subframe timeslot number,and the system bandwidth, among the resource groups.

Further optionally, the random function is a hash (Hash) function.

In the ECSS resource determining device provided by the embodiment ofthe present invention, for an ECCS for transmitting common controlinformation, physical resources of the ECCS are allocated reasonably,but no method relating to reasonable allocation of physical resourcesoccupied by an ECCS is available in the prior art; therefore, theembodiment of the present invention eliminates a blind area in design,achieves inter-cell interference coordination and a frequency domaindiversity gain, and improves transmission reliability of common controlinformation of an EPDCCH.

Another embodiment of the present invention further provides a basestation, which is used in a cross-carrier scheduling process, where anEPDCCH candidate on at least two carriers is located in an EPDCCHresource set on one carrier among the at least two carriers, anaggregation level of the EPDCCH is L, and L>=1. The base stationincludes: an ECSS resource determining device and a sending device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The sending device is configured to place the ECSS in a physicalresource, determined by the ECSS resource determining device, occupiedby the ECSS, and send a carrier in which the ECSS is placed.

An embodiment of the present invention further provides a UE, which isused in a cross-carrier scheduling process, where an EPDCCH candidate onat least two carriers is located in an EPDCCH resource set on onecarrier among the at least two carriers, an aggregation level of theEPDCCH is L, and L>=1. The UE includes: an ECSS resource determiningdevice and a receiving device.

The EPDCCH candidate determining device is configured to determine theEPDCCH resource set p in a subframe k, where the EPDCCH resource set pincludes q resource block pairs, each of the resource block pairscorresponds to r enhanced control channel elements ECCEs, q>=1, r>=1,N_(ECCE,p,k)=q×r indicates the number of ECCEs in the EPDCCH resourceset p, reference numerals of the N_(ECCE,p,k) ECCEs are 0, 1, 2, . . . ,N_(ECCE,p,k)−1 respectively, an EPDCCH candidate of the EPDCCH at theaggregation level L corresponds to L ECCEs having consecutive referencenumerals, and an EPDCCH candidate is capable of carrying an EPDCCH; anddetermine the number of EPDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an ECCE correspondingto each EPDCCH candidate, where the ECCE corresponding to each EPDCCHcandidate at the aggregation level L is related to the index Cellindex.

The receiving device is configured to detect the ECSS in a physicalresource, determined by the ECSS resource determining device, occupiedby the ECSS, and obtain common control information of a cell by means ofparsing.

Another embodiment of the present invention further provides an ECSStransmission system, which includes the foregoing base station and UE inthis embodiment.

In the base station, the UE, and the ECSS transmission system providedby the embodiment of the present invention, for an ECCS for transmittingcommon control information, physical resources of the ECCS are allocatedreasonably, but no method relating to reasonable allocation of physicalresources occupied by an ECCS is available in the prior art; therefore,the embodiment of the present invention eliminates a blind area indesign, achieves inter-cell interference coordination and a frequencydomain diversity gain, and improves transmission reliability of commoncontrol information of an EPDCCH.

Through the foregoing description of the embodiments, a person skilledin the art may clearly understand that the present invention may beimplemented by software in addition to necessary universal hardware, anddefinitely may also be implemented by hardware. However, under mostcircumstances, the former is preferred. Based on such an understanding,the technical solutions of the present invention essentially, or thepart contributing to the prior art may be implemented in the form of asoftware product. The computer software product is stored in a readablestorage medium, for example, a floppy disc, a hard disk, or an opticaldisc of a computer, and includes several instructions for instructing acomputer device (which may be a personal computer, a server, or anetwork device) to perform the methods described in the embodiments ofthe present invention.

The foregoing descriptions are merely specific embodiments of thepresent invention, but are not intended to limit the protection scope ofthe present invention. Any variation or replacement readily figured outby a person skilled in the art within the technical scope disclosed inthe present invention shall fall within the protection scope of thepresent invention. Therefore, the protection scope of the presentinvention shall be subject to the protection scope of the claims.

What is claimed is:
 1. A physical downlink control channel (PDCCH)candidate determining method for use in a cross-carrier schedulingprocess, wherein a PDCCH candidate on at least two carriers is locatedon a physical downlink control channel resource set on one carrier amongthe at least two carriers, an aggregation level of the PDCCH is L, andL>=1, the method comprising: determining, by a base station, an PDCCHresource set p in a subframe k, wherein the PDCCH resource set pcomprises N_(ECCE,p,k) control channel element (CCE), a PDCCH candidateof the PDCCH at the aggregation level L corresponds to L CCEs havingconsecutive reference numerals, and an PDCCH candidate is capable ofcarrying a PDCCH; and determining, by the base station, the number ofPDCCH candidates at the aggregation level L of a carrier correspondingto an index Cellindex and an CCE corresponding to each PDCCH candidate,wherein the CCE corresponding to each PDCCH candidate at the aggregationlevel L is related to the index Cellindex.
 2. The PDCCH candidatedetermining method according to claim 1, wherein determining the numberof PDCCH candidates at the aggregation level L of a carriercorresponding to an index Cellindex and an CCE corresponding to eachPDCCH candidate comprises: obtaining an CCE corresponding to an m^(th)PDCCH candidate according to the following formula:${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$wherein Y_(p,k) is a random value related to the subframe number k andthe PDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of PDCCH candidates, of a user equipment UE corresponding to thePDCCH candidate, corresponding to the aggregation level L of the PDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.
 3. The PDCCH candidate determining method according to claim2, wherein: n_(Cellindex) is a relative offset, which is related to theindex Cellindex, of candidates having a same serial number betweencarriers; and a value range of n_(Cellindex) is from 0 to the number D1of carriers in carrier aggregation of the user equipment minus 1 or tothe number D2 of schedulable carriers of the user equipment in the PDCCHset minus 1, and the D2 schedulable carriers comprises carriersactivated and deactivated in the PDCCH set p by the user equipment inthe subframe k.
 4. The PDCCH candidate determining method according toclaim 2, wherein according to ascending order or descending order of theindexes Cellindex of the carriers, a first serial number sequence, whichis sequentially numbered, is obtained starting from 0, and n_(Cellindex)is a serial number value of the carrier index Cellindex in the firstserial number sequence.
 5. The PDCCH candidate determining methodaccording to claim 2, wherein: n_(Cellindex) is a value of the indexCellindex.
 6. A physical downlink control channel (PDCCH) candidatedetermining device for use in a cross-carrier scheduling process,wherein an PDCCH candidate on at least two carriers is located on aphysical downlink control channel resource set on one carrier among theat least two carriers, an aggregation level of the PDCCH is L, and L>=1,the device comprising: a processor; and a memory for storing programcode which, when executed by the processor, causes the PDDCH determiningdevice to: determine a PDCCH resource set p in a subframe k, wherein thePDCCH resource set p comprises N_(ECCE,p,k) control channel element(CCE), a PDCCH candidate of the PDCCH at the aggregation level Lcorresponds to L CCEs having consecutive reference numerals, and anPDCCH candidate is capable of carrying an PDCCH, and determine thenumber of PDCCH candidates at the aggregation level L of a carriercorresponding to an index Cellindex and an CCE corresponding to eachPDCCH candidate, wherein the CCE corresponding to each PDCCH candidateat the aggregation level L is related to the index Cellindex.
 7. ThePDCCH candidate determining device according to claim 6, wherein todetermining the number of PDCCH candidates at the aggregation level L ofa carrier corresponding to an index Cellindex and an CCE correspondingto each PDCCH candidate, the program code, when executed by theprocessor, causes the PDDCH determining device to: obtain a CCEcorresponding to an m^(th) PDCCH candidate according to the followingformula:${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$wherein Y_(p,k) is a random value related to the subframe number k andthe PDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of PDCCH candidates, of a user equipment UE corresponding to thePDCCH candidate, corresponding to the aggregation level L of the PDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.
 8. The PDCCH candidate determining device according to claim7, wherein n_(Cellindex) is a value of the index Cellindex.
 9. A basestation for use in a cross-carrier scheduling process, wherein aphysical downlink control channel (PDCCH) candidate on at least twocarriers is located on a PDCCH resource set on one carrier among the atleast two carriers, an aggregation level of the PDCCH is L, and L>=1,the base station comprising: a processor; a memory for storing programcode which, when executed by the processor, causes the base station to:determine a PDCCH resource set p in a subframe k, wherein the PDCCHresource set p comprises N_(ECCE,p,k) control channel element (CCE), aPDCCH candidate of the PDCCH at the aggregation level L corresponds to LCCEs having consecutive reference numerals, and a PDCCH candidate iscapable of carrying a PDCCH, and determine the number of PDCCHcandidates at the aggregation level L of a carrier corresponding to anindex Cellindex and an CCE corresponding to each PDCCH candidate,wherein the CCE corresponding to each PDCCH candidate at the aggregationlevel L is related to the index Cellindex; and a transmitter configuredto place a PDCCH of a carrier, whose index Cellindex is a carrierindicator field index Cellindex, in one PDCCH candidate among PDCCHcandidates determined by the base station, and send the PDCCH.
 10. Thebase station according to claim 9, wherein to determine the number ofPDCCH candidates at the aggregation level L of a carrier correspondingto an index Cellindex and an CCE corresponding to each PDCCH candidate,the program code, when executed by the processor, causes the basestation to: obtain a CCE corresponding to an m^(th) PDCCH candidateaccording to the following formula:${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$wherein Y_(p,k) is a random value related to the subframe number k andthe PDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of PDCCH candidates, of a user equipment UE corresponding to thePDCCH candidate, corresponding to the aggregation level L of the PDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.
 11. The base station according to claim 10, whereinn_(Cellindex) is a value of the index Cellindex.
 12. A user equipment(UE) for use in a cross-carrier scheduling process, wherein a physicaldownlink control channel (PDCCH) candidate on at least two carriers islocated on a PDCCH resource set on one carrier among the at least twocarriers, an aggregation level of the PDCCH is L, and L>=1, the UEcomprising: a processor; a memory for storing program code which, whenexecuted by the processor, causes the UE to: determine a PDCCH resourceset p in a subframe k, wherein the PDCCH resource set p comprisesN_(ECCE,p,k) control channel element (CCE), a PDCCH candidate of thePDCCH at the aggregation level L corresponds to L CCEs havingconsecutive reference numerals, and a PDCCH candidate is capable ofcarrying a PDCCH, and determine the number of PDCCH candidates at theaggregation level L of a carrier corresponding to an index Cellindex anda CCE corresponding to each PDCCH candidate, wherein the CCEcorresponding to each PDCCH candidate at the aggregation level L isrelated to the index Cellindex; and a receiver configured to: detect thePDCCH candidate determined by the UE, when a correct PDCCH is detected,obtain control information of the carrier, whose index Cellindex is acarrier indicator field index Cellindex, from the correct PDCCH by meansof parsing.
 13. The UE according to claim 12, wherein to determine thenumber of PDCCH candidates at the aggregation level L of a carriercorresponding to an index Cellindex and an CCE corresponding to eachPDCCH candidate, the program code, when executed by the processor,causes the UE to: obtain a CCE corresponding to an m^(th) PDCCHcandidate according to the following formula:${L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + n_{Cellindex}} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i$wherein Y_(p,k) is a random value related to the subframe number k andthe PDCCH resource set p, p and k are both integers, M_(p) ^((L)) is thenumber of PDCCH candidates, of a user equipment UE corresponding to thePDCCH candidate, corresponding to the aggregation level L of the PDCCHresource set p, 0<=i<=L−1, 0<=m<=M_(p) ^((L))−1, and n_(Cellindex) is apredefined candidate offset of the carrier corresponding to the indexCellindex.
 14. The base station according to claim 13, whereinn_(Cellindex) is a value of the index Cellindex.